Early insulin sensitivity after restrictive bariatric surgery, inconsistency between HOMA-IR and steady-state plasma glucose levels
Received 9 July 2009; received in revised form 1 November 2009; accepted 18 November 2009. published online 10 December 2009.
Abstract
Background
The low-grade inflammatory condition present in morbid obesity is thought to play a causative role in the pathophysiology of insulin resistance (IR). Bariatric surgery fails to improve this inflammatory condition during the first months after surgery. Considering the close relation between inflammation and IR, we conducted a study in which insulin sensitivity was measured during the first months after bariatric surgery. Different methods to measure IR shortly after bariatric surgery have given inconsistent data. For example, the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) levels have been reported to decrease rapidly after bariatric surgery, although clamp techniques have shown sustained insulin resistance. In the present study, we evaluated the use of steady-state plasma glucose (SSPG) levels to assess insulin sensitivity 2 months after bariatric surgery.
Methods
Insulin sensitivity was measured using HOMA-IR and SSPG levels in 11 subjects before surgery and at 26% excess weight loss (approximately 2 months after restrictive bariatric surgery).
Results
The SSPG levels after 26% excess weight loss did not differ from the SSPG levels before surgery (14.3 ± 5.4 versus 14.4 ± 2.7 mmol/L). In contrast, the HOMA-IR values had decreased significantly (3.59 ± 1.99 versus 2.09 ± 1.02).
Conclusion
During the first months after restrictive bariatric surgery, we observed a discrepancy between the HOMA-IR and SSPG levels. In contrast to the HOMA-IR values, the SSPG levels had not improved, which could be explained by the ongoing inflammatory state after bariatric surgery. These results suggest that during the first months after restrictive bariatric surgery, HOMA-IR might not be an adequate marker of insulin sensitivity.
aNutrition and Toxicology Research Institute Maastricht (NUTRIM), Department of General Surgery, Maastricht University/University Hospital Maastricht, Maastricht, The Netherlands
bDepartment of Internal Medicine, Maastricht University/University Hospital Maastricht, Maastricht, The Netherlands
Correspondence: Jeroen Nijhuis, M.D., Ph.D., Department of General Surgery, Maastricht University/University Hospital Maastricht, P.O. Box 616, Maastricht 6200 MD, The Netherlands
ABSTRACT